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Conduction in ionic organic plastic crystals: the role of defects

journal contribution
posted on 31.10.2006, 00:00 authored by J Huang, A Hill, Maria ForsythMaria Forsyth, D MacFarlane, A Hollenkamp
This paper describes the relationship between the ionic conduction and the characteristics of defects in plastic crystalline phases of N,N-dimethylpyrrolidinium bis(trifluoromethanesulfonyl)amide (P 11 TFSA). Positron annihilation lifetime spectroscopy (PALS) shows that the phase III to phase II transition involves the generation and expansion of vacancies, which is confirmed by measurement of volumetric expansion. The vacancies expand to match the cation size in phase II and this gives rise to an increase in the conductivity. The relationship between the vacancy volume and the conductivity obeys a Cohen-Turnbull free volume conduction model. The critical volume matches the volume of a cation-anion pair in phase III, which indicates a Schottky mechanism. The critical volume shows a greater value in phase II, which is probably indicative of a pipe diffusion mechanism.

History

Journal

Solid state ionics

Volume

177

Issue

26-32

Season

Special issue: Solid state ionics 15: proceedings of the 15th international conference on solid state ionics, part II

Pagination

2569 - 2573

Publisher

Elsevier

Location

Amsterdam, The Netherlands

ISSN

0167-2738

eISSN

1872-7689

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

2006, Crown Copyright